1. Field of the Invention
The present invention is generally directed to an implantable medical device using transcutaneous radio frequency magnetic induction links between external and implantable components, and more particularly to a multi-coil wireless communication system for an implantable medical device.
2. Related Art
Auditory prostheses, such as cochlear implants, have typically comprised an external component, such as a speech processor unit, and an implantable component, such as a receiver/stimulator unit. The external component can comprise a casing, a microphone, a speech processor that converts detected sounds into coded signals and a power source. The implantable component receives the coded signals and power from the external component and outputs a stimulation signal to an electrode assembly which applies electrical stimulation to the auditory system of the implantee producing a hearing sensation corresponding to the original detected sound.
Communication between the external component and the implantable component can be provided by a radio frequency (RF) magnetic induction link comprising an external antenna and an internal implanted antenna. This (RF) link provides transcutaneous transmission of the coded signals to, and also typically from, the implantable component and can also serve to provide power to the implantable component. Such a prosthesis can utilize more than one type of external component or work together with other external or implantable components.
Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application.